Measurement of the iodine uptake by the thyroid: comparative analysis between the gamma camera system with 'pinhole' collimator and 13S002 system

The thyroid uptake measurements are common in medical uses and are considered a direct and precise form of diagnostic, however, different results have been observed as measurements of thyroid uptake are taken using distinct equipment. This study attempts to find the cause of the differences between a thyroid uptake probe and a gamma camera. These discrepancies can be associated to the different patients samples, equipment's problems or operator procedures errors. This work presents the results of comparative uptake measurements performed in a neck phantom and a 4-hour thyroid uptake study in 40 patients, using a Gamma Camera Ohio Nuclear model Sigma 410 with a pinhole collimator and Nuclear Medicine System model 13S002, developed by Instituto de Engenharia Nuclear. The results observed show that in spite of non satisfactory results commented in literature, both the System 13S002 and System Gamma Camera Ohio can be used in uptake thyroid diagnostic with statistical confidence degree of 99 %. (author)